By the end of the twentieth century, most Latin American countries could look back on their longest uninterrupted and, as of this writing, still open-ended period of political democracy. No country except Chile and Uruguay had enjoyed a longer run of full or even constrained democratic competition in any previous era. Before 1980, only five Latin American countries had achieved episodes of more than twelve continuous years of democratic or semidemocratic rule, but by 1999 that threshold had been crossed by no fewer than six additional countries. By the turn of the millennium, four of the five countries with comparatively durable democratic experiences before 1970 had once again accumulated a record of more than twelve years of continuous democracy since their most recent democratic transitions. Consequently, Latin America stands out as the most uniformly democratic region on earth behind the established Western democracies and Japan. This is evidenced in Table I.1, which is based on Larry Diamond's recoding of Freedom House regime scores (Diamond 2002: 29–30, table 2).

Because of the regional prevalence and durability of democracy in Latin America since the 1980s, research on the region has begun to move away since the mid-1990s from the theme of political regime change and has started to focus more on the empirical “quality” of democratic institutions and processes of authoritative decision making. Our study contributes to this field of investigations.